Container locating and vacuum sensing system



y 6, 1968 H. J. KEINANEN 3,392,329

CONTAINER LOCATING AND VACUUM SENSING SYSTEM Filed Jan. 10, 1966 4 Sheets-Sheet l July 16, 1968 H. J. KEINANEN 3,392,829

CONTAINER LOCATING AND VACUUM SENSING SYSTEM Filed Jan. 10, 1966 4 Sheets-Sheet 2 [www- July 16, 1968 H. J. KEINANEN 3,392,329

CONTAINER LOCATING AND VACUUM SENSING SYSTEM Filed Jan. 10, 1966 4 Sheets-Sheet 5 m m u m x *1 QQN UNRWQ ESQ Jjff 6757? f/ anarzem July 16, 1968 KEINANEN 3,392,829

CONTAINER LOCATING AND VACUUM SENSING SYSTEM Filed Jan. 10. 1966 4 Sheets-Sheet 4 I I I vI I a, coIvnucnvE VEI- V22 IIm/II/II/I United States Patent Office 3,392,829 Patent ed July 16, 1968 3,392,829 CONTAINER LOCATING AND VACUUM SENSING SYSTEM Henry J. Keinanen, Hickory Hills, 11]., assignor to Continental Can Company, Inc., New York, N.Y., a corporation of New York Filed Jan. 10, 1966, Ser. No. 519,597 16 Claims. (Cl. 209-74) ABSTRACT OF THE DISCLOSURE A system for locating a vacuumized container at a detecting station and determining the condition of a top panel or a panel and the closure lid thereon which indicates the vacuum or pressure condition within the container wherein apparatus is employed which utilizes the eflect of electrical conducting material upon the induction of a sensing coil to indicate the proximity of the electrical conducting material without contacting the material, the apparatus including a set of posit-ion sensing coils which actuate an electrical circuit when a container is loacted in proper position beneath a second set of coils which detect whether the top panel is concave as a result of a vacuum condition within the container or convex as a result of the loss of vacuum. The apparatus includes an ejector which is activated to reject from the line a container reaching the detecting station with the toppanel which is convex due to loss of vacuum.

This invention relates generally to assorting solids, such as containers, which are vacuum sealed by metal closure members, and is particularly concerned with automatic systems employing magnetism to effect the sorting operation.

In the vacuum packaging of certain materials, for example, baby foods and various food products, it is conventional practice to pack the material in glass jars or containers which are sealed with metal caps of the type having a central portion which is flexed downwardly by atmospheric pressure to a lower than normal elevation or height with respect to the peripheral portions of the cap as long as the desired vacuum is maintained in the container. When the vacuum in the container is less than the normal amount or is completely missing the normally flexed portion of the cap rises as it returns to an unflexed position. When this condition exists, as it sometimes does, due to failure of the cap applying and sealing mechanism to function properly, or due to the presence of a defective or damaged container or cap, the container or package is termed a dud and it is desirable to separate it from the containers which have been properly sealed and in which the proper vacuum condition exists. Since containers of this character are processed, at speeds ranging up to 2,000 per minute, it is desirable to provide a detecting mechanism which is capable of eflicient operation on containers traveling at a rate of speed which may be relatively high. Also, considerable tolerance is allowed in the manufacture of glass jars and like containers so that it is desirable to provide a mechanism which will perform its detecting function in spite of the presence of normally expected variations in the dimensions of the jars and caps.

Various apparatus and arrangements have heretofore been provided for incorporation in a vacuum packing line so as to detect containers in which the required vacuum conditions are lacking. One such arrangement is disclosed in R. C. Bailey Patent No. 3,206,027, dated Sept. 14, 1965, which is operative to detect the presence of a sealed container in which the vacuum has been reduced below a predetermined minimum by measuring changes in the height of deflectable portions of the metal caps on the containers and detecting when such changes exceed a predetermined value. However, this detecting apparatus and most other apparatus provided for this purpose includes a sensing arm which rides on or contacts the container and which, at high speeds, is rendered virtually inoperative, due to the bouncing or fluttering action which results from rapid contact with successive containers.

It is a general object of the present invention to provide an apparatus which utilizes the effect of electrically conductive material upon the inductance of a sensing coil to indicate the proximity of the electrically conductive material, for accurately sensing the position of an electrically conductive metallic object or an object formed of or including electrically conductive material, such as a metal closure cap or a plastic closure cap having metal flakes therein on a jar or a container, for the purpose of initiating the beginning or completion of an operation upon the object or a related element, and a cooperating sensing apparatus for detecting a particular configuration, condition or position of the object, for example, the contour of a portion of the top panel of a container closure cap, when the cap is in a predetermined position where it act'uates the position sensing apparatus, and which may operate, through appropriate electric circuitry, a container reject device so as to separate selected containers having an improper vacuum condition from a line thereof which is conveyed past the sensing and detecting apparatus.

A more specific object of the invention is to provide an apparatus for sensing the position and the vacuum condition of a jar or other container which is closed by a metallic lid and vacuum sealed, wherein the apparatus utilizes the effect of metallic material upon the inductance of a sensing coil to indicate the proximity of the metallic material Without contacting the material, and wherein one set of coils is employed to detect the presence and position of a container while a second set is employed to compensate for variations in the proximity and to detect contour variations of the top panel in the lid which varies according to the vacuum conditions within the container and thereby serves to indicate whether proper vacuum has been maintained within the container or whether there is a lack of proper vacuum due to improper sealing or any other condition resulting in leakage.

A still more specific object of the invention is to provide an apparatus which is adapted: to sense the presence of an object exhibiting electrically responsive properties, such as a metal closure member or cap used in the vacuum sealing of a container for any of several purposes, such as counting the number of such objects as they are moved, one by one, past a detecting station, determining that the object, if a closure member for a vacuum sealed container, is in position at the detecting station to enable the apparatus to indicate whether it is properly sealed, etc; to sense the presence of the object without making physical contact therewith; to measure variations in the contour of the object or, when the object is a metal closure member, to measure the contour of a portion of the closure member relative to other portions thereof, without contact therewith in order to ascertain whether there is a predetermined vacuum within the container; and to effect an operation, such as the ejection of a container from a succession of them moved through the detecting station one by one, as a result of the detection of a departing from the normal condition of the closure member for the container due to loss of vacuum therein when the container is at the detecting station.

These and other objects and advantages of the invention will be apparent from a consideration of the apparatus which is shown by way of illustration in the accompanying'drawings wherein:

FIGURE 1 is a perspective view, somewhat diagrammatic in character, illustrating the application of the system of the present invention for the detection of containers not properly vacuum sealed and herein referred to as duds;

FIGURE 2 is a vertical sectional view, also somewhat diagrammatic in character, taken generally along the line 22 of FIGURE 1;

FIGURE 3 is a vertical sectional view taken generally along the line 33 of FIGURE 2;

FIGURE 4 illustrates diagrammatically the circuit connections that can be employed in practicing this invention; and

FIGURE 5 shows a number of curves that demonstrate certain operating characteristics of the invention.

Referring now to FIGURES l and 2 of the drawings, the reference character designates, generally, a system for sensing the position of and whether a proper vacuum seal is maintained between a closure member or cap 11 and a container 12, such as a container for foodstulf, formed of a suitable material such as glass. The closure member or cap 11 is formed of or includes electrically conductive material.

The containers 12 vacuum sealed by the electrically conductive closure member or cap 11 are moved by a conveyor belt 13, one by one, past a detecting station, indicated generally at 14, the movement being in the direction indicated by arrows 15 in FIGURES 1 and 3. Side guides 16 serve to maintain the containers 12 centered with respect to the conveyor belt 13. An opening is provided in one of the side guides 16 where a chute 17 is located over which duds can be ejected. For this pur pose a dud ejector, indicated generally at 18, is employed. The dud ejector 18 can employ any suitable motor mechanism such as an air driven piston carrying a ram 19 having a head 20 at its distal end for engaging the dud to be ejected through the chute 17.

When the electrically conductive closure member or cap 11 is properly vacuum sealed to the container 12, certain portions of it are at predetermined heights or elevations relative to other portions thereof. In order to sense the relative heights of the various portions thereof, height sensing windings A, B and C are employed. They are located centrally of and along the paths of the closure member or cap 11 and the container 12 as it moves through the detecting station 14. The number of turns on the windings A and C are equal while the number of turns on the winding B is equal to the sum of the number of turns on windings A and C. The windings A, B and C are provided with centrally located magnetic cores 21, 22 and 23, which, under normal operating conditions with a properly sealed container 12 supported with the cap 11 in a level position beneath the coils A, B and C, are spaced, as indicated in FIGURE 3, equally at 24, 25 and 26 from juxtaposed portions of the upper side of the closure member or cap 11. It will be observed that the spacings 24 and 26 are at diametrically opposite positions of the rim 27 of the closure member or cap 11 While the spacing 25 is between the lower end of the core 22 and the upper side of a flip panel 28 which forms a part of the closure member of cap 11 and is in the concave position shown in FIGURE 3 when normal vacuum is present in the container 12. It will be observed that the lower end of the magnetic core 22 for the winding B is positioned at a lower elevation than the lower ends of the cores 21 and 23 for the windings A and C. The reason for this is that the spacings 24, 25 and 26 should be equal under proper vacuum conditions in a normal container 12 which is supported with the cap 11 in a level position, while the central portion of the flip panel 28 is at a lower elevation than the portions of the rim 27 that are juxtaposed to the lower ends of the magnetic cores 21 and 23.

The windings A and C are connected in series aiding 4 circuit relation in a leg of a bridge circuit which also includes coil B and capacitors 29 and 30 that are interconnected by a potentiometer 31. The bridge circuit is energized from a current source, such as an oscillator 32, arranged to provide, for example, 29 volts regulated at a frequency of the order of 3,000 cycles per second. Under normal operating conditions with a container of normal height and not tilted and with the spacings 24, 25 and 26 being equal, the bridge circuit is balanced when energized in the manner described. However, as described hereinafter, should there be an absence of a predetermined vacuum in the container 12, the flip panel 28 shifts from the downwardly dished or concave position shown in FIGURES 2 and 3 to the upwardly dished or convex position indicated at 28 in FIGURE 2. When this takes place, while the spacings 24 and 26 do not change, the spacing at 25 does change with a corresponding change in the magnetic circuit for the winding B. As a result, the bridge circuit is unbalanced and a signal is provided indicating the presence of a dud which should be removed. Should the closure member or cap have a dent near the center of the flip panel of sufiicient depth to create a signal above the critical level, such a defective container will also be rejected in the same manner as a dud. A container also may be rejected if its cap has a deep dent on the rim portion. Such dented caps occur now and then and heretofore it has been necessary to rely on visual observation to detect the same. The over-all height of the capped container, within normal height variations, does not change the operation, since changes in over-all height will affect all three coils A, B and C equally. Also, tilting of the container, within limits, will not change the operation since tilting will not change the total voltage drop across the two coils A and C. That is to say, as the space 24- for example is decreased because of the tilting of the cap, the space 26 will be increased a like amount so that the total additive voltage drop across both coils A and C remains approximately the same as would exist with a level cap. Tilting of the cap in the opposite direction gives the same result. Coils A and C are thus effective as compensating windings to compensate for small variations in the height of the containers or for slight tilting within the normal expected tolerance limits.

It is to be understood that if tilted caps are never encountered, successful operation can be achieved by using only one of the coils A or C, but in such case the one coil used should be the same or nearly the same size as the coil B. This single coil A or C adjacent the rim of the cap will compensate for the expected height variation of the containers.

It is evident that the relationship between the closure member or cap 11 and the windings A, B and C should be substantially as shown in FIGURE 3 for a proper determination of the position of the flip panel 28. Thus the position of the container 12 and thereby of the closure member or cap 11 along the path of movement thereof are ascertained accurately to the end that the signal resulting from the unbalancing of the bridge circuit, previously described, is effective to operate the dud ejector 18 only when the closure member or cap 11 is located substantially in the position relative to the three coils A, B and C as shown in FIGURE 3. For this purpose, position detecting windings D1 and D2 are located alongside of the path of closure member or cap 11 in the relationship shown in FIGURES 1, 2 and 3. When the closure member or cap 11 is accurately located or positioned in the detecting station 14 the position detecting windings D1 and D2 are located on opposite sides of and equidistant from a line along a diameter of closure member or cap 11 at right angles to the diameter along which the height sensing windings A, B and C are located. The position detecting windings D1 and D2 are provided with magnetic cores 35 and 36 which are inclined with respect to the horizontal plane of the top of the closure member or cap 11. These windings are connected with capacitors 37 and 38 in a bridge circuit and to a potentiometer 39. The bridge circuit is energized from the oscillator 32. In FIGURE 4 the bridge circuits are shown being energized individually from the oscillator 32. However, the oscillator 32 is common to all of the bridge circuits shown.

It will be understood that the bridge circuit including the position detecting windings D1 and D2 with the capacitors 37 and 38 and energized from the oscillator 32 is balanced either when the closure member or cap 11 is symmetrically positioned with respect to these windings, as shown in FIGURES 1 and 3, or in the absence of the closure member or cap 11. Accordingly, it is necessary to provide for determining that the closure member or cap 11 is present at the time that the bridge circuit including the position detecting windings D1 and D2 is in balance. For this purpose, proximity detecting windings E1 and B2 are employed. The proximity detecting winding E1 is located midway between the position detecting windings D1 and D2 and somewhat to the left of them as shown in FIGURE 2. Magnetic cores 40 and 41 are provided for the proximity detecting windings E1 and E2. The proximity detecting windings E1 and B2 are connected in a bridge circuit that includes capacitors 42 and 43 which are interconnected by a potentiometer 44 and energized from the oscillator 32. While only the proximity detecting winding E1 is affected by the presence or absence of the closure member or cap 11, the proximity detecting winding E2 is employed which is a duplicate of winding E1 for bridge balancing and temperature compensating functions.

As illustrated in FIGURE 2, the several windings A, B, C, D1, D2, E1 and E2 are mounted on a floor 47 of suitable insulating material such as plastic with the respective magnetic cores extending therethrough. The windings are enclosed in a housing 48 that is formed of ferromagnetic material such as sheet steel. The housing 48 is provided with side Walls 49 and 50, FIGURE 3, and end walls 51 and 52. A partition 53 of ferromagnetic material is interposed between the height sensing windings A, B and C and the position detecting windings D1 and D2 and proximity detecting windings E1 and E2. The partition 53 acts as a magnetic shield to prevent interaction between the height sensing windings A, B and C and the other windings.

It is desirable that the several windings be maintained at a constant temperature that is somewhat in excess of the usually variable ambient temperature incident to the container 12 which may pass through the detecting station 14 at a temperature above room temperature. In order to maintain such a condition, heaters 54 and 55 are located in the two spaces within the housing 48 and are suitably energized from a current source and controlled to maintain the desired constant operating temperature of the several windings.

The proper functioning of the system depends upon the location of the height sensing windings A, B and C; of the position detecting windings D1 and D2 and of the proximity detecting winding E1 in fairly close proximity to the electrically responsive closure member or cap 11, although they are not required to have physical engagement therewith. It sometimes happens that the closure member or cap 11 is improperly located on the container 12 and projects an abnormal height thereabove and to such an extent that it might contact the housing 48 in passing through the detecting station 14. With a view of swinging the housing 48 and parts assembled therewith out of the path of such a faulty container assembly, the end wall 52 is hinged at 56 to a frame member 57. The floor 47 is provided with an upwardly curved ramp 58, FIGURE 3, which is engageable by the abnormally positioned closure member or cap 11 and co-operates therewith to shift the housing 48 upwardly. If a capped container is above normal height but not high enough to contact the housing the spacing from all three coils A, B, and C is altered equally and there is no elIect on the detecting function.

The same applies if the capped container is below normal height but Within acceptable tolerance.

FIGURE 4 shows the circuit connections that can be employed in conjunction with the three bridge circuits previously described. The control circuit is energized from a suitable 12 volt direct current regulated source represented by conductors 74 and 75, the latter being grounded. A voltage divider 76 is connected between the conductors 74 and and includes voltage dividing resistors R1, R2 and R3 connected in series. An adjustable tap 77 provides connection to the resistor R1. The control circuit employed in conjunction with the three bridge circuit includes transistors Q1, Q2, Q3, Q4, Q5 and Q6. Transistors Q5 and Q6 are connected to a 17 volt direct current source which is represented by the conductors 78 and 75, the latter being the grounded conductor.

The transistor Q2 normally is conducting and thus effectively grounds voltage divider resistor R2. As the closure member of cap 11 enters the detecting station 14, it passes in close proximity to position detecting winding D2 and the voltage drop the-reacr-oss increases as shown by curve 80 in FIGURE 5. This is followed by a similar increase in the voltage drop across position detecting winding D1 represented by curve 81. The balance of the position detector bridge including the position detecting windings D1 and D2 is thus upset and an indication thereof is applied to primary winding 82F of a transformer 82 which has a secondary winding 828 that transfers the signal to the circuitry associated with transistor Q3. The transistor Q3 begins to conduct and provides a parallel path to ground for the voltage divider resistor R2 with the transistor Q2 which, it will be recalled, is normally conducting. The transistor Q3 begins to conduct when the bridge circuit including the position detecting windings D1 and D2 is upset to a critical level. This is indicated at 83 along curve 80 which corresponds to the curve 80, the hatched area thereunder indicating the time that the transistor Q3 remains in the conducting state. In the meantime, as the closure member or cap 11 continues in its forward movement into the detecting station 14, it comes underneath the proximity detecting winding E1. The balance of this bridge is upset and a signal is applied to primary winding 84F of a transformer 84 having a secondary winding 848. This results in rendering transistor Q1 conducting. When this occurs transistor Q2 is rendered non-conducting with the result that the ground is maintained across the section R2 of the voltage dividing resistor 76 only by the transistor Q3 remaining conducting for the balance of the cross hatched area underneath curve 80. Transistor Q2 is rendered non-conducting as indicated at 85 on curve 86 when transistor Q1 becomes conducting.

Curve 87 in FIGURE 5 shows that voltage across proximity detecting Winding E1 is increasing while the voltage represented by curve 80 is decreasing. There is a short interval indicated at 88 during which transistor Q3 is rendered non-conducting. This interval corresponds to the maximum voltage across proximity detecting winding E1 as represented by curve 87. During this interval 88, while transistor Q3 is non-conducting, the ground across the section R2 of the voltage divider resistor 76 is completely removed. -It is only during this period, which corresponds to the position of the closure member or cap 11 symmetrically with respect to the height sensing windings A, B and C as shown in FIGURE 1, that a dud detecting signal can be effectively given for operating the dud ejector 18. In the presence of a dud, the balance of the bridge including the height sensing windings A, B and C is upset and a signal is thereby applied to primary winding 90B of a transformer 90, inducted into a secondary winding 90S and applied across parallel connected diodes 91 in the circuit that extends from the adjustable tap 77. Assuming that the dud detecting signal is obtained during the interval indicated at 88 in FIGURE 5, when the section R2 of the voltage dividing resistor 76 is ungrounded, transistor Q4 is rendered conducting. Following transistor Q4 becoming conducting, transistor Q5 is rendered conducting and it times the duration of the interval during which transistor Q6 is rendered conducting. Briefly stated, transistor Q4 triggers Q5 and since transistors Q5 and Q6 are connected to perform as a oneshot multivibrator, the output pulse from Q6 has always a constant length.

On transistor Q6 having been rendered conducting and assuming the switch 92 is closed, operating winding 93 of a solenoid valve 94 is energized. This valve is opened to permit air from air intake 95 to flow into the dud ejector 18 for extending the ram 19 and causing the head 20 to engage the container 12 and eject it into the chute 17. On deenergization of the solenoid valve 94, air is exhausted from the dud ejector 18 through exhaust SP6 and the ram 19 is returned by spring action.

As the closure member ll continues to move through the inspecting station 14, the voltage applied to primary winding 821 of the transformer $2 is such that transistor Q3 again begins to conduct as indicated by curve 81' and the hatched area thereunder. Again the section R2 of the voltage dividing resistor 76 is grounded. The closure member 11 passes beyond the proximity detecting winding E1 and the voltage thereacross as indicated by curve 87 decreases with the result that transistor Q1 is rendered nonconducting and transistor Q2 again becomes conducting as indicated at 97 on curve 36. Finally, the closure member 11 moves beyond the position detecting winding E1 and transistor Q3 is rendered non-conducting. However, since transistor Q2 is now conducting, the section R2 of the voltage dividing resistor as is effectively grounded.

With ferrous metal closure members or caps the circuitry employed will respond sufliciently to insure proper detection of variations in the contour of that portion of the closure member which is affected by changes in internal pressures in the container. With closure members made of materials not exhibiting ferromagnetic properties but which have some degree of electrical responsiveness it may be necessary or desirable to adjust the circuitry, or provide some additional amplification to bring the weaker signal up to an operating level. When aluminum or other caps, not exhibiting ferromagnetic properties to an appreciable degree, are used as container closures eddy currents are induced therein which cause sufficient voltage variation across the detecting coils for detecting purposes.

What is claimed as new is:

1. A system for sensing contour variation of electrically responsive closure members on sealed containers as they are moved along a path, one by one, past a detecting station without requiring physical contact between the sensing means and the closure members or containers, said system comprising: means responsive to the presence of a closure member only when it is in said detecting station, means disposed in a fixed position relative to the path of the containers and spaced therefrom which is responsive to variations in contour of said closure member in said detecting station, and means responsive to operation of said contour responsive means and to said means responsive to the presence of a closure member when said closure member varies from a predetermined desired contour and only when said container is in said detecting station.

2. A system for sensing contour variation of electrically responsive closure members on sealed containers as they are moved along a path, one by one, past a detecting station without requiring physical contact between the sensing means and the closure members or containers, said system comprising: mean responsive to the presence of a closure member only when it is in said detecting station, including first and second position winding means past which said container is movable and substantially symmetrically located with respect to said closure memher in said detecting station, means responsive to variations in contour of said closure member in said detecting station, and means responsive to operation of said contour responsive means and to said first and second position winding means when said closure member varies from a predetermined contour and is substantially symmetrically located with respect to said first and second position winding means.

3. A system for sensing contour variation of electrically responsive closure members on sealed containers as recited in claim 2, and said means responsive to the presence of a closure member only when it is in said detecting station including also proximity winding means past which said container is movable and located substantially midway between said first and second position winding means; and said means which is responsive to operation of said contour responsive means and said first and second position winding means being responsive to operation of said proximity winding means when said closure member varies from a predetermined contour, is substantially symmetrically located with respect to said first and second position winding means, and is operatively related to said proximity winding means.

4. A system for sensing contour variations of electrically responsive closure members on sealed containers as recited in claim 3; and said means which is responsive to variations in contour of said closure member in said detecting station, including first and second closure member proximity variation compensating winding means past which said container is movable and located substantially at diametrically opposite locations with respect to the rim of said closure in said detecting station, and a third closure member contour variation sensing winding means past which said container is movable and located substantially midway between said first and second closure member proximity variation compensating winding means; and said means which is responsive to operation of said contour responsive means being responsive to operation of said first and second proximity variation compensating winding means and said third closure member contour variation sensing winding means, of said first and second position winding means, and of said proximity winding means when the proximity of a portion of said closure member varies with respect to any one of said winding means of said means which is responsive to variations in contour, by a predetermined amount, when said closure member is substantially symmetrically located with respect to said first and second position winding means, and is operatively related to said proximity winding means.

5. A system for sensing contour variations of electrically responsive closure members on sealed containers as they are moved along a normal path, one by one, past a detecting station without requiring physical contact between the sensing means and the closure members or containers and being capable of ejecting certain of said containers from said path, said system comprising: means responsive to the presence of a closure member only when it is in said detecting station, means disposed in fixed position at said detecting station and responsive to contour variations of said closure member in said detecting station, means for ejecting a container from said normal path, and means for effecting the operation of said ejecting means in response to operation of said contour responsive means and to said closure member detecting means when said closure member varies from a predetermined desired contour and only when said container to be ejected is in said detecting station.

6. A system for sensing contour variation of electrically responsive closure members on sealed containers as they are moved along a normal path, one by one, past a detecting station without requiring physical contact between the sensing means and the closure members or containers and being capable of ejecting certain of said containers from said path, said system comprising: means responsive to the presence of a closure member only when it is in said detecting station, means disposed in fixed position at said detecting station and responsive to contour variations of said closure member in said detecting station, means for ejecting a container from said normal path, means for effecting the operation of said ejecting means in response to operation of said contour responsive means and to said closure member detecting means when said closure member varies from a predetermined desired contour and only when said container to be ejected is in said detecting station, and said means responsive to the presence of a closure member only when it is in said detecting station, including first and second position winding means past which said container is movable and substantially symmetrically located with respect to said closure member in said detecting station, and said means for effecting operation of said ejecting means being operative in response to operation of said contour responsive means and of said first and second position winding means when said closure member varies from a predetermined desired contour and only when the closure member on said container to be ejected is substantially symmetrically located With respect to said first and second position winding means.

7. A system -for sensing contour variation of electrically responsive closure members on sealed containers as recited in claim 6 and said means responsive to the presence of a closure member only when it is in said detecting station including also proximity winding means past which said container is movable and located substantially midway between said first and second position winding means; and said means for effecting operation of said ejecting means being operative in response to operation of said contour responsive means, of said first and second position winding means and of said proximity winding means when said closure member varies from a predetermined desired contour, is substantially symmetrically located with respect to said first and second position winding means, and is operatively related to said proximity winding means.

8. A system for sensing contour variation of electrically conductive closure members on sealed containers as they are moved along a normal path, one by one, past a detecting station without requiring physical contact between the sensing means and the closure members or containers and ejecting certain of said containers from said path, said system comprising: means responsive to the presence of a closure member only when it is in said detecting station including first and second position winding means past which said container is movable and substantially symmetrically located with respect to said closure member in said detecting station, and proximity winding means past which said container is movable and located substantially midway between said first and second position winding means; means responsive to contour variations of said closure member in said detecting station including first and second closure member proximity variation compensating winding means past which said container is movable and located substantially at diametrically opposite locations with respect to the rim of said closure member in said detecting station, and a third closure member contour Sensing winding means past which said container is movable and located substantially midway between said first and second closure member proximity variation compensating winding means; means for ejecting a container from said normal path, and means for effecting operation of said ejecting means in response to operation of said first and second closure member proximity variation compensating winding means and said third closure member contour sensing winding means, of said first and second position winding means, and of said proximity winding means when the contour of said clo sure member varies from a predetermined desired contour, when the closure member on said container to be ejected is substantially symmetrically located with respect to said first and second position winding means, and is operatively related to said proximity winding means.

9. Means for sensing the presence of objects such as electrically conductive closure caps, as they are moved along a path, one by one, past a detecting station without requiring physical contact between the sensing means and the objects, said object sensing means comprising: first and second position winding means spaced along said path adjacent said detecting station past which each object is movable and substantially symmetrically located with respect to said object in said detecting station, and means responsive to operation of said first and second position winding means when said object is substantially symmetrically located with respect to said first and second position winding means.

10. Means for sensing the presence of objects such as electrically conductive closure caps, as they are moved along a path, one by one, past a detecting station without requiring physical contact between the sensing means and the objects, said object sensing means comprising: first and second position winding means spaced along said path adjacent said detecting station past which each object is-movable and substantially symmetrically located with respect to said object in said detecting station, means responsive to operation of said first and second position winding means when said object is substantially symmetrically located with respect to said first and second winding means and said object sensing means comprising also proximity winding means past which said object is movable and located substantially midway between said first and second position winding means and said means which is responsive to operation of said first and second position winding means being responsive also to operation of said proximity winding means when said object is substantially symmetrically located with respect to said first and second position winding means and operatively related to said proximity winding means.

11. A system for sensing the degree of variation in height of electrically conductive closure members on sealed containers as they are moved along a path, one by one, past a detecting station without requiring physical contact between the sensing means and the closure members or containers, .said system comprising: first and second closure member proximity variation compensating winding means located substantially at diametrically opposite positions with respect to the rim of said closure member in said detecting station, a third closure member contour sensing winding means located substantially midway between said first and second closure member contour sensing winding means, and means responsive to operation of said first, second and third winding means when the proximity of a portion of said closure member with respect to any one of said winding means varies a predetermined amount.

12. A system for sensing contour variation of electrically responsive closure members on sealed containers as they are moved along a normal path, one by one, past a detecting station without requiring physical contact between the sensing means and the closure members or containers and ejecting certain of said containers from said path, said system comprising: means responsive to the presence of a closure member only when it is in said detecting station, means responsive to contour variations of said closure member in said detecting station, means for ejecting a container from said normal path, means for eftecting the operation of said ejecting means in response to operation of said contour responsive means and to said means responsive to the presence of a closure member when said closure member contour varies from a predetermined desired contour and only when said container to be ejected is in said detecting station, support means carrying said detecting means and said contour responsive means and supporting the same in operative relation to said closure members as said containers are moved along said path, means movably mounting said support means, and means on said support means engageable with any of said closure members positioned at an abnormal height on the respective container for bodily moving said detecting means and said contour variation responsive means out of the path of such abnormally high closure members to prevent damage thereof.

13. The invention, as set forth in claim 4, wherein magnetic shield means is interposed between the first, second and third winding means of the said means responsive to variation in contour of the closure member and the position and proximity winding means to prevent interaction between said winding means.

14. A system for sensing the degree of variation in contour of an electrically responsive object positioned at a detecting station without requiring physical contact between the sensing means and the object, said system comprising: first means responsive to the presence of said object only when it is in predetermined position at said detecting station, second means positioned in fixed noncontacting relation relative to said object which second means is responsive to variations in the contour of a portion of said object relative to adjacent portions thereof, and means responsive to operation of said first means and said second means when said variation exceeds a predetermined Value.

15. A system for sensing the contour variation of electrically responsive closure members on sealed containers positioned at a detecting station Without requiring physical contact between the sensing means and the closure members or containers, said system comprising: at least one proximity variation compensating winding means located closely adjacent a rim portion of said closure member, and a closure member contour sensing winding means located closely adjacent a flexible container sealing top panel portion of said closure member, and means responsive to operation of all of said winding means when there is a variation in the contour of the top panel portion of said closure member which exceeds a predetermined value.

16. In a system for sensing variation in the contour of portions of an electrically responsive container wall rela tive to the normal plane of said container wall when the container is positioned at a detecting station without requiring physical contact between the sensing means and said container wall, first and second wall proximity variation compensating winding means located at spaced apart locations adjacent said wall and a third contour variation sensing winding means located substantially midway be tween said first and second wall proximity variation compensating winding means, and means responsive to operation of said first, second and third winding means when there is a variation in the contour of a predetermined portion of said wall midway between said first and second winding means relative to the normal plane of said wall.

References Cited UNITED STATES PATENTS 2,791,730 5/1957 Stout 209-111.8 3,064,807 11/1962 Stover 209-111.8X 3,206,027 9/1965 Bailey 209-1l1.8 3,295,676 1/1967 Ochs 209- 111.s

ALLEN N. KNOWLES, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,392 ,829 July 16 1965 Henry J. Keinanen It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 22, "loacted" should read located Column 2, line 67, "departing" should read departure Column 9, line 75, beginning with "9. Means for sensing" cancel all to and including "position winding means." in line 12. Column 10; line l3, "10." should read 9. line 35, "11." should read l0. line 52, "12." should read ll. Column 11, line 4, "15." should read l2. line l0, "14." should read l3. line 23, "15." should read 14. Column 12, line 6, "16." should read l5.

In the heading to the printed specification, line 8, "16 Claims." should read 15 Claims Signed and sealed this 6th day of January 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents 

